In the field of filament winding of threads or ribbons of fibres on a mandrel, it is common to place the latter on a machine that imparts thereto a generally rotational movement by which the mandrel draws off the thread and winds it onto itself. According to other known techniques, for example for the purpose of producing and winding around tubes, a frame is provided to revolve around an article that winds the thread about the said article, which can itself have imparted to it a movement relative to the frame. In all cases, the thread or the fibre intended to form the filamentary winding is dispensed from a reel which is usually formed by a cylindrical cardboard support onto which the thread is wound, which reel is capable of maintaining the thread in wound condition and allows it to wind off under the traction effect caused by the movement of the mandrel. In certain special cases, more precisely when the thread has to be wound onto an irregularly shaped support, it must be possible for the thread to be wound off from the reel at a constant tension so that winding around the article also takes place in a manner that is constant, whatever the configuration of the article to be wound. This tension must further be adjustable by the user in accordance with the winding sought after, and classical dispensing reels do not afford this possibility. Certain windings also necessitate large quantities of thread, and when a reel is empty, it is then necessary to substitute a fresh reel therefor, and consequently, interrupt winding in order to bond together the strands from the two reels. If a previous dispensing tension has been set for the first reel, the setting has to be repeated so that this pretensioning is also applied to the second reel, which is not always easy to achieve with the classical dispensing reels.
There are known, of course, systems of housings containing threads or ribbons that unwind when pulled upon and that rewind when released, such as, for example, an electric cable drum, a tape measure or a dog leash. But none of these systems possesses the new mechanical functions necessitated by the modern techniques of filament winding, which require means for replenishment with thread and for unwinding thread continuously at a constant adjustable tension, as indicated above.